1. Field of the Invention
This invention is in the field of protective enclosures for electrical wiring (i.e., junction boxes). More particularly, this invention relates to a non-conductive junction box for electrical wiring and related electrical components. Junction boxes are generally manufactured and supplied to the trade in industry-standard sizes and configurations. Some conventional junction boxes are made entirely or partially of conductive metallic material, but increasingly the electrical trade, and especially some particular applications such as electrical wiring in wet environments, call for junction boxes that are formed entirely of non-conductive materials.
2. Related Technology
Generally, electrical wiring terminations and electrical components are installed within protective junction boxes in both residential and industrial environments. Typically, such electrical components and wiring terminations must be installed into and attached to a junction box so as to provide proper spacing between components, to provide environmental protection to the wiring terminations and components, and to prevent inadvertent contact with the wiring and components, for example, by people or animals. An important consideration is that a junction box be as spacious inside as is practicable for a particular size class in order to provide adequate room for the wiring terminations, and also be very flexible in the methods allowed for routing wires and conduits to and from the junction box.
Another consideration with junction boxes is the size or sizes of electrical conduits that are to be connected with the junction box. Conventional junction boxes generally allow only a single size of electrical conduit to be connected to a particular junction box. Some junction boxes will accept connection of a couple of different sizes of electrical conduits, or require the use of adapters or reducer bushings to facilitate connection of more than one or two different sizes of electrical conduits. Consequently, installers of electrical junction boxes and wiring must carry to job sites a great multitude of different sizes and configurations of conventional junction boxes so that they can be sure of having what they need for a particular job.
Over the years there have been many types of electrical junction boxes developed, some for specialized usage and others for more generalized purposes, often with a view to both low cost of manufacture and to economy of use. The main purposes of such junction boxes have been to provide environmental protection for wiring terminations and electrical components installed in the boxes, while also preventing inadvertent contact by humans and animals with this wiring and electrical components.
Junction boxes have been designed in many and varying shapes and sizes, but have these above-described conventional considerations and functions in common. Many junction boxes are made to industry standard or to trade standard sizes. Earlier, junction boxes were generally constructed of metal and had only preformed knockouts for the attachment of conduits. When the electrician or installer found it necessary to have a hole for wire or conduit access to a junction box, this installer used a tool, such as either a punch or screwdriver, to remove a preformed knockout.
More recently, junction boxes have been constructed of plastics, or a mix of metals and plastics, and provide a wide variety of configurations for standard and for specialized uses. Conventional junction boxes which may be relevant to this invention include those set out in the following United States patents:
U.S. Pat. No. 5,169,013, issued 8 Dec. 1992, to Albert Lammens, Jr.;
U.S. Pat. No. 5,216,203, issued 1 Jun. 1993, to Edward E. Gower;
U.S. Pat. No. 5,352,850, issued 4 Oct. 1994, to Trevor W. Norris;
U.S. Pat. No. 5,541,363, issued 30 Jul. 1996, to Gary K. Weise, et al. (a named coinventor on the present application);
U.S. Pat. No. 5,828,001, issued 27 Oct. 1998, to Jan J. Schilhiam;
U.S. Pat. No. 5,936,200, issued 10 Aug. 1999, to Mike K. Park; and
U.S. Pat. No. 5,942,726, issued 24 Aug. 1999, to Kenneth Reiker.
A significant disadvantage of conventional junction boxes results from their comparative inflexibility of configuration, installation, size expansion capability; and particularly limitations with respect to inflexibility for routing and attachment of electrical conduits.
In view of the deficiencies of the conventional related technology, it is an object of this invention to overcome one or more of these deficiencies.
This invention provides a molded non-conductive plastic junction box that has an interior volume which is larger than that of conventional junction boxes of the same exterior size. The present inventive junction box has a back wall and four contiguous side walls, each joined both to the back wall and to it""s two contiguous side walls. The side walls are arranged in spaced apart opposite pairs and each side wall terminates at an end edge in a common plain with the other side walls to cooperatively define an opening into the box. This opening is used to insert components and wiring into the box and may be overlaid with a cover plate to provide a dry, non-corrosive, and economical enclosure.
The junction box includes mounting lugs adjacent to this opening for securing a cover plate to the box as well as for securing at least one electrical component inside the box. These mounting lugs extend from the plane of the junction box opening toward but short of the back wall of the box in order to provide increased interior volume for the junction box. Also, the wall portion of the junction box inwardly of the termination of these mounting lugs (i.e., toward the back wall of the box) provides additional wall space to which conduit sockets may be mounted, if desired.
The present inventive junction box body includes a unique insert member, which is receivable into an insert recess of the junction box, and which insert member defines one or more conduit sockets at which conduits may be coupled to the junction box body. Thus, by using a certain size of junction box body, and having a variety of different sizes and configurations (i.e., single, or double conduit sockets, for example) of insert members, an installer is able to make at a job site a wide variety of different junction box assemblies. This combination of features results in a greater utility for the junction box combinations, reduced costs, and reduced storage space and inventory size requirements for the inventive junction box assembly, when compared to those requirements for conventional junction boxes offering the same installation possibilities.
Accordingly, according to one embodiment, this invention provides an electrical junction box, this junction box comprising: a molded plastic junction box body including a back wall, and plural contiguous walls extending generally perpendicularly to the back wall, and each one of the plural contiguous walls joining integrally to the back wall and also to adjacent ones of the plural contiguous walls to cooperatively define a chamber within the junction box, with the plural contiguous walls at respective end edges cooperatively forming an opening to the chamber; at least one wall of the junction box body defining an insert recess for slidably receiving an insert member which carries at least one conduit socket into which a termination portion of an electrical conduit may be secured.
Other objects, features, and advantages of the present invention will be apparent to those skilled in the art from a consideration of the following detailed description of two exemplary preferred embodiments of the inventive junction box, when taken in conjunction with the appended drawing Figures. In these appended drawing Figures, features which are the same or which are analogous in structure or function are indicated by the same reference numeral throughout the several views.